This paper presents the characteristics of tapered roller bearings (TRBs) taking into consideration the effects of tapered roller angle error which may occur during manufacturing. To this end, a TRB model including tapered roller angle errors was developed. The effects of tapered roller angle error on the contact load distribution, bearing stiffness and fatigue life were investigated with respect to changes in the tapered roller angle error. A statistical analysis of the fatigue life of TRBs was also provided with respect to tapered roller angle error. Simulation results show that the tapered roller angle error changes the load distribution of the rollers and causes angular misalignment in TRBs, and subsequently, influences the bearing stiffness and fatigue life. The statistical analysis shows that the Weibull distribution is an acceptable method to represent the statistical fatigue life for the practical range of tapered roller angle errors.

Displacement ductility and rotational ductility are used, to verify the performance of blast doors subjected to explosive loads. The values of these performance items are calculated by measuring the maximum elastic displacement in the laboratory, and the maximum displacement during the explosion test. To attain the maximum elastic displacement, the finite element analysis and the load distribution method are applied. In applying the load distribution method, the behavior of a blast door along a width direction is converted to a cantilever beam and along a height direction to a simply supported beam. The results by the load distribution method are verified by a finite element analysis and compared with those by a plate theory.